1. Field of the Invention
The present invention relates to a method and a device for producing ammonia from biomass and, more particularly, to a method and a device for producing ammonia with improved efficiency while consuming less energy.
2. Description of the Related Art
Conventionally, ammonia is produced through the Haber process (also known as the Haber-Bosch process or the Fritz-Haber process). However, the chemical reconstitution is slow in reactive efficiency. Thus, the conventional method can not fulfill economic need.
Pursuant to continuing improvement in the converting techniques for converting bioenergy, bioenergy conversion has been widely applied in various processes in the chemistry industries. More importantly, various elements contained in the air are important sources for bioenergy conversion and recycling. At the present stage, elements contained in the air can be converted into useful materials through burning, thermal chemical conversion or biochemical conversion, seeking reduction in the consumed energy for producing ammonia while attaining recycling of environmental elements.
In Taiwan Patent Publication No. 200510249 entitled “METHOD FOR THE POINT OF USE PRODUCTION OF AMMONIA FROM WATER AND NITROGEN”, a method for producing high-purity ammonia, high-purity hydrogen and high-purity nitrogen out of deionized water and standard nitrogen is proposed. In this method, oxygen is removed from the deionized water, and the oxygen-free deionized water is sent to an electrolytic hydrogen generator to produce hydrogen. Then, the hydrogen is purified and mixed with purified nitrogen. The mixture of the purified hydrogen and the purified nitrogen is then compressed. The compressed mixture is sent to a catalytic ammonia reactor for purification. Finally, the nitrogen, the purified hydrogen and the purified nitrogen are sent to a semiconductor processing machine.
Conventionally, pure gaseous nitrogen directly reacts with gaseous hydrogen obtained from water electrolysis to form the ammonia. However, the bond strength between the hydrogen atom and the oxygen atom of liquid water at normal temperature and normal pressure does not permit separation of the hydrogen atom from the oxygen atom. An external strong current must be provided to electrolyze liquid water to obtain gaseous hydrogen and gaseous oxygen, which consumes considerable energy and requires a long period of time of electrolysis to release sufficient gaseous hydrogen. Thus, the yield of gaseous hydrogen is low, because it is obviously limited to the reaction time of water electrolysis. This leads to a low production efficiency of the gaseous hydrogen, affecting the production efficiency and yield of subsequently formed ammonia.
Furthermore, during the process of electrolyzing the liquid water into gaseous hydrogen and gaseous oxygen, only the gaseous hydrogen is used to react with the gaseous nitrogen to obtain ammonia. Namely, the oxygen is not effectively used, leading to waste and failing to meet the goal of recovering energy.
Thus, a need exists for a method and a device for producing ammonia with improved production efficiency while recovering energy.